A Scanner Darkly

John W. Campbell Memorial Award: Best Novel nominee (1978).

Cops and criminals have always been interdependent, but no novel has explored that perverse symbiosis more powerfully than A Scanner Darkly. Bob Arctor is a dealer of the lethally addictive drug called Substance D. Fred is the police agent assigned to tail and eventually bust him. To do so, he has taken on the identity of a drug dealer named Bob Arctor. And since Substance D – which Arctor takes in mammoth doses – gradually splits the user's brain into two distinct, combative entities, Fred doesn't realize that he is narcing on himself.